Calendering as a direct shaping tool for the continuous production of fixed-dose combination products via co-extrusion

In this study calendering is used as a downstream technique to shape monolithic co-extruded fixed-dose combination products in a continuous way. Co-extrudates with a metoprolol tartrate-loaded sustained-release core and a hydrochlorothiazide-loaded immediate-release coat were produced and immediately shaped into a monolithic drug delivery system via calendering, using chilled rolls with tablet-shaped cavities. In vitro metoprolol tartrate release from the ethylcellulose core of the calendered tablets was prolonged in comparison with the sustained release of a multiparticulate dosage form, prepared manually by cutting co-extrudates into mini-matrices. Analysis of the dosage forms using X-ray micro-computed tomography only detected small differences between the pore structure of the core of the calendered tablet and the mini-matrices. Diffusion path length was shown to be the main mechanism behind the release kinetics. Terahertz pulsed imaging visualized that adhesion between the core and coat of the calendered tablet was not complete and a gradient in coat thickness (varying from 200 to 600 μm) was observed. Modulated differential scanning calorimetry and X-ray diffraction indicated that the solid-state properties of both drugs were not affected by the calendering procedure.     

DNA strand breaks induced by nuclear hijacking of neuronal NOS as an anti-cancer effect of 2-methoxyestradiol

2-Methoxyestradiol (2-ME) is a physiological metabolite of 17β-estradiol. At pharmacological concentrations, 2-ME inhibits colon, breast and lung cancer in tumor models. Here we investigated the effect of physiologically relevant concentrations of 2-ME in osteosarcoma cell model. We demonstrated that 2-ME increased nuclear localization of neuronal nitric oxide synthase, resulting in nitro-oxidative DNA damage. This in turn caused cell cycle arrest and apoptosis in osteosarcoma cells. We suggest that 2-ME is a naturally occurring hormone with potential anti-cancer properties.     

Lack of association of the Glu298Asp polymorphism of endothelial nitric oxide synthase with manifest coronary artery disease,carotid atherosclerosis and forearm vascular reactivity in two Austrian populations

OBJECTIVE: Conflicting data exists about the possible contribution of the homozygous Asp/Asp genotype of the Glu298Asp polymorphism of endothelial nitric oxide synthase to human atherosclerotic vascular disease. We investigated the polymorphism in two independent study populations: a case-control study including patients with angiographically verified coronary artery disease (CAD) on the one hand and a cross-sectional epidemiological study on the other hand. METHODS: The Glu298Asp polymorphism was determined by PCR-RFLP as established. In the case-control study (240 patients and 248 controls) a possible association between the polymorphism and CAD, and age of onset of CAD and myocardial infarction was investigated. In the cross-sectional epidemiological study (932 subjects) intima-media thickness (IMT) of the carotid artery as well as morphological plaque burden and forearm vascular reactivity (peak postischemic reactive hyperaemia, determined by venous occlusion plethysmography) were measured. RESULTS: In the case-control study genotype distribution (Glu/Glu; Glu/Asp; Asp/Asp) was not different between the CAD patients (43/46/11%) and the controls (49/41/10%, P = NS). No association of the polymorphism with age of onset of CAD or myocardial infarction was found. In the epidemiological study no influence of the genetic variant on IMT was observed after correction for classical determinants of IMT (average IMT: Asp/ Asp: 0.077 +/- 0.011 mm; Glu/Glu and Glu/Asp: 0.080 +/- 0.012 mm, P = NS). Forearm vascular reactivity was also not different between homozygous Asp/Asp subjects and Glu/Glu and Glu/Asp subjects (peak-reactive hyperaemia 20.1 +/- 7.3 mL min-1 100 mL-1 vs. 20.0 +/- 6.5 mL min-1 100 mL-1, P = NS). CONCLUSIONS: Our results suggest that there is no association of the Glu298Asp polymorphism with coronary or carotid atherosclerosis or forearm vascular reactivity in these populations recruited in a country with a rather high risk for atherosclerosis. We suggest additional investigations to be performed in populations at different risk for coronary events to further elucidate the possible contribution of this polymorphism to vascular disease.     

Red blood cell rheology in sepsis

Changes in red blood cell (RBC) function can contribute to alterations in microcirculatory blood flow and cellular dysoxia in sepsis. Decreases in RBC and neutrophil deformability impair the passage of these cells through the microcirculation. While the role of leukocytes has been the focus of many studies in sepsis, the role of erythrocyte rheological alterations in this syndrome has only recently been investigated. RBC rheology can be influenced by many factors, including alterations in intracellular calcium and adenosine triphosphate (ATP) concentrations, the effects of nitric oxide, a decrease in some RBC membrane components such as sialic acid, and an increase in others such as 2,3 diphosphoglycerate. Other factors include interactions with white blood cells and their products (reactive oxygen species), or the effects of temperature variations. Understanding the mechanisms of altered RBC rheology in sepsis, and the effects on blood flow and oxygen transport, may lead to improved patient management and reductions in morbidity and mortality.     

Role of Oestrogen Receptors on the Modulation of NADPH‐Diaphorase‐Positive Cell Number in Supraoptic and Paraventricular Nuclei of Ovariectomised Female Rats

Modulation of the nitric oxide producing system (demonstrated via the NADPH‐diaphorase histochemical reaction) by oestradiol has been established in several structures of the rat brain. The present study aimed to explore the possible regulation of NADPH‐diaphorase activity by oestradiol in neurones of the supraoptic (SON) and paraventricular (PVN) nuclei and the role of oestrogen receptors (ERα and ERβ) in this regulation. Adult ovariectomised rats were divided into six groups and injected either with vehicle or a single dose of oestradiol, a selective ERα agonist‐PPT [4,4′,4″‐(4‐propyl‐[1H]‐pyrazole‐1,3,5‐triyl)trisphenol], a selective ERβ agonist‐DPN [2,3‐bis(4‐hydroxyphenyl)‐propionitrile], a selective ERα antagonist‐MPP [1,3‐bis(4‐hydroxyphenyl)‐4‐methyl‐5‐[4‐(2‐piperidinylethoxy)phenol]‐1H‐pyrazole dihydrochloride] or a selective ERβ antagonist‐PHTPP (4‐[2‐phenyl‐5,7‐bis(trifluoromethyl)pyrazolo[1,5‐a]pyrimidin‐3‐yl]phenol). The number of NADPH‐diaphorase positive elements in the SON and the PVN was modulated by both ERs but, depending on the nucleus, ERα and ERβ ligands induced different effects. These results suggest that the regulation of nitrergic system by ERs may play a role in the control of oestrogen‐dependent physiological mechanisms regulated by the SON and the PVN.     

高血糖大鼠海马CA1区一氧化氮合成酶阳性神经元变化的研究

Nitricoxide（NO）isanewneurotransmitter，existsincentralnervoussystemwidelyandtakespartinnerveconductionandreg－ulationofcerebralbloodstream犤１犦．Butthechangeofnitricoxidesynthetase（NOS）positiveneuronshasn＇tbeenreportedindetail．WeadopthistochemicalmethodtoobserveNOSpositiveneuronsinhippocampusCA１ofratswithhyperglycemia．１Materialsandmethods１．１GroupsandanimalmodelsDivide４０Wistarratsweighted２００～２５０ginto３groups．Normalcontrolgroup（NC）：２０rats．Hyperglycemiagroup（D…     

The cyclopentenone prostaglandin 15-deoxyΔ12,14-prostaglandin J2 attenuates the development of zymosan-induced shock

Objective Multiple-organ failure (MOF) is defined as the progressive deterioration in function which occurs in several organs or systems in patients with septic shock, multiple trauma, severe burns, or pancreatitis. This study investigated the effect of 15-deoxy-^12,14-PGJ₂ (15d-PGJ₂), a PPAR- ligand, in a model of zymosan-induced nonseptic shock in mice.Materials and methods Mice were randomly assigned to one of four groups (n=10 each) and treated i.p. as follows: group 1, zymosan (500 mg/kg suspended in saline solution) and vehicle (10% DMSO); group 2, zymosan (500 mg/kg suspended in saline solution) plus 15d-PGJ₂ (30 µg/kg, suspended in 10% DMSO) 1 h before and 6 h after zymosan administration; group 3, 15d-PGJ₂ (30 µg/kg, suspended in 10% DMSO; group 4, vehicle for PGJ₂ (10% DMSO) always 1 h before and 6 h after saline administration. After 18 h mice were killed and tissues and biological fluids used for biochemical, immunohistochemical, and histological analysis.Measurements and results 15d-PGJ₂ inhibited the inflammatory response and significantly reduced peritoneal mononuclear cell infiltration and histological injury in mice. A significant protection was demonstrated in kidney, liver, and pancreas injury by the reduction in amylase, lipase, creatinine, AST, ALT, bilirubin, and alkaline phosphatase levels. 15d-PGJ₂ also reduced the appearance of nitrotyrosine in the inflamed intestinal tissues. Histological examination revealed a significant reduction in zymosan-induced intestinal damage in 15d-PGJ₂ treated mice.Conclusions Our findings demonstrate that 15d-PGJ₂ exerts potent anti-inflammatory effects on zymosan-induced shock.Electronic Supplementary Material Electronic supplementary material to this paper can be obtained by using the Springer Link server located at .     

糖尿病酮症酸中毒兔血-脑脊液屏障的变化

目的　探讨糖尿病酮症酸中毒的血脑脊液屏障损伤机制。方法　新西兰家兔随机分模型组(n=6 )和生理盐水对照组 (n=6 )。模型组从耳缘静脉注射四氧嘧啶和链脲佐菌素各 15 0 mg/ kg,对照组给予等量生理盐水 ,72 h后检测血糖、尿酮体。两组静脉内均注射伊文氏蓝 ,6 h后检测动脉血气 ;处死动物 ,取脑组织用紫外分光光度计测定伊文氏蓝吸光度 (A) ,并观察光镜、超微结构、碱性磷酸酶细胞化学及诱导型一氧化氮合酶 (i NOS)免疫组织化学结果。结果　 72 h后模型组 :血糖全部大于 17mm ol/ L,尿中出现酮体 ;伊文氏蓝 A值略增高 ,和对照组相比无显著性差异。组织学和超微结构观察模型组脑血管周围水肿 ,内皮细胞损伤 ,神经元变性、坏死。碱性磷酸酶细胞组化显示血管内皮上酶活性明显弱于对照组。免疫组化可见脑实质内血管壁上 i NOS染色阳性。结论　在四氧嘧啶和链脲佐菌素诱发的糖尿病酮症酸中毒动物模型中出现脑水肿 ,其产生与血脑脊液屏障的破坏及一氧化氮 (NO)参与有关。     

Endothelial dysfunction in streptozotocin-diabetic rats is not reversed by dietary probucol or simvastatin supplementation

Summary Oxidative stress and dyslipidaemia are key features of diabetes mellitus and may be involved in mediating the vascular endothelial dysfunction associated with this disease. The aim of this study was to examine the effect of dietary lipid-lowering and antioxidant agents on vascular endothelial function and oxidative stress. Diabetic male Sprague-Dawley rats (i. v. streptozotocin, 45 mg/kg) were fed for 4 weeks on a standard diet or on a diet supplemented with either the lipid-lowering antioxidant probucol (1 % w/w in diet) or the 3-hydroxy 3-methylglutaryl coenzyme-A (HMG-CoA) reductase inhibitor simvastatin (0.01 % w/w in diet). Responses to noradrenaline, acetylcholine, and sodium nitroprusside were assessed in small mesenteric arteries (mean internal diameter 300 ± 5 μm, n = 80) mounted on a small vessel myograph. Plasma concentrations of total cholesterol and triglycerides were significantly raised in standard-fed diabetic rats and significantly reduced in probucol and simvastatin-fed diabetic rats. 8-epi-prostaglandin (PG)F₂α, an indicator of oxidative stress, was raised in liver and aorta from diabetic rats compared to controls. Probucol supplementation reduced 8-epi-PGF₂α in aorta and liver of diabetic rats but increased 8-epi-PGF₂α content in plasma and aorta from control animals. The abnormal relaxation to acetylcholine in arteries from the diabetic rats (pEC₅₀ diabetic 6.763 ± 0.172 vs control 7.541 ± 0.175; p < 0.05) was not improved by probucol or simvastatin. These data, therefore, do not support a role for oxidative stress or dyslipidaemia in mediating the impaired ACh-induced endothelium-dependent relaxation of small mesenteric arteries from the streptozotocin-diabetic rat. [Diabetologia (1998) 41: 157–164] Received: 4 August 1997 and in revised form: 29 September 1997